My invention relates generally to coke oven doors and more particularly to leveler doors for sealing the leveler opening in coke oven doors.
A coke oven door on the pusher side of the oven is usually provided with an opening near the top to permit the insertion of a leveler bar therethrough. The leveler bar is pushed into the coke oven chamber and reciprocally moved several times until the surface of the coal charge in the oven is substantially leveled. When the leveler bar is withdrawn from the coke oven, the leveler opening is closed using a door or lid, and the coking process is begun. During the coking process, gaseous distillation products are formed which result in the condensation of tar and pitch-like deposits in the area of the coke oven door and particularly its leveler door. If sulfur bearing coal is coked, a corrosive gas is, likewise, evolved. Heretofore, the leveler doors most commonly used are of heavy cast iron and a metal to metal seal is effected around the leveler opening by machining the edge of the leveler door and its corresponding seating surface on the cast iron coke oven door. These cast iron leveler doors have proved to be expensive and unsatisfactory in that the sealing edge of the door and its corresponding seating surface must be repeatedly cleaned to remove the tarry deposits in order to maintain the required metal to metal seal. If the seal area is not cleaned, the seal between the leveler door and over door is not achieved and gases escape. The case iron leveler doors and seating surfaces, likewise, are attacked by the corrosive gases generated by the coking process. Periodically, the coke oven doors must be removed from the coke ovens and the sealing surfaces of the leveler doors and seating surfaces are rebuilt by deposition of weld metal and subsequent machining operation. If these expensive maintenance operations are not frequently done, the build-up of tarry deposits and the action of the corrosive gases cause gaps between the conventional leveler door and its seating surface which results in the harmful emission of gaseous distillation products into the atmosphere. Prior attempts have been made to solve the problems of sealing leveler doors, for example, U.S. Pat. Nos. 2,442,391 - Wilputte, and 2,820,002 - Wolff. These attempts have not been completely successful in that they require relatively complicated leveler door constructions which are expensive to manufacture and maintain.
My invention solves the problems heretofore encountered by providing a leveler door which effectively seals the leveler opening and greatly reduces the maintenance previously required by such doors.
My invention further provides a leveler door which slidably engages the seating surface adjacent the leveler opening during closing and tightly seals the leveler opening due to its flexible, concave shape.
My invention still further provides a leveler door and sealing seat which are capable of withstanding the corrosive effects of the coke oven gases.
My invention further provides a leveler door which is adapted for use on any of the various coke oven doors used in the industry.
Briefly, my invention provides a leveler door for sealing the leveler opening in a coke oven door; the oven door of the type having conventional leveler door mounting and latching apparatus associated therewith. The leveler door of my invention comprises a flexible closure member, preferably stainless steel, possessing spring-like properties at elevated temperatures. The closure member has a generally concave shape and terminates in a flexible sealing edge at its outer periphery. The sealing edge is formed at an angle of less than 90.degree. relative to the plane of the leveler opening. Means for securing the closure member to the mounting and latching apparatus of the oven door are provided whereby the compressive closing force supplied by the mounting and latching apparatus causes the rear of the concave closure member to move toward the leveler opening, causing the sealing edge to concurrently flex outwardly from the leveler opening while slidably engaging the coke oven door adjacent the leveler opening. In the closed position, the concave shape of the closure member springably maintains the flexible sealing edge in compressive and sealing engagement with the area adjacent the leveler opening. A corrosion resistant and heat resistant sealing seat may also be provided on the oven door surrounding the leveler opening. The corrosion resistant sealing seat further reduces the need for maintenance and insures a more uniform and longer life seal between the leveler door and the oven door.